Stroke is no longer regarded as an untreatable condition with
inevitable long-term morbidity. The current drive to establish more
stroke units in South African (SA) public and private hospitals is to be
commended. [1] There is robust evidence in the medical literature to
indicate that treating stroke patients in a multidisciplinary stroke
unit significantly reduces death and dependency. [2] The components of
care that are probably responsible for this improved outcome include
good nursing care, protocol-driven care with attention to swallowing,
hydration, nutrition, early detection of complications of stroke and
early rehabilitation.

Intravenous thrombolysis with tissue plasminogen activator (tPA)
has become the standard of care in specialised stroke units for selected
patients who can be treated within 4.5 hours of onset of symptoms.
Irrespective of age or stroke severity, and despite an increased risk of
fatal intracranial haemorrhage during the first few days after
treatment, intravenous tPA significantly improves the overall odds of a
good stroke outcome when delivered within 4.5 hours of stroke onset,
with earlier treatment associated with bigger proportional benefits. [3]
This treatment should only be provided in stroke centres, where the
staff are trained to administer thrombolysis for stroke using a clear
protocol with access to early brain imaging, laboratory facilities and
neurosurgical advice.

Emerging treatment--mechanical thromb ectomy

Until recently, intravenous tPA has been the only reperfusion
therapy proven to reduce disability after acute ischaemic stroke.
Although intravenous tPA is effective at recanalising more distal
thrombi, it is less successful in dissolving larger more proximal
thrombi. [4] Randomised trials published in the past year have shown
significant benefit of mechanical thrombectomy within 6 hours of onset
over best medical treatment in patients with acute ischaemic stroke due
to proximal large-vessel occlusion (terminal internal carotid, middle
cerebral and anterior cerebral arteries), with an absolute benefit
(modified Rankin score 0-2 at 90 days) for functional outcome ranging
from 13.5% to 31% for thrombectomy over best medical treatment. [5-9]
The development of more effective devices has allowed reopening of
vessels in up to 84.5% of patients. [10] Currently the most effective
option is the use of retrievable stents, which are deployed into the
thrombus and then pulled out together with the clot that is occluding
the affected vessel. The results of these recently published trials for
acute ischaemic stroke herald the beginning of a new era in the
treatment of patients with large-vessel occlusion amenable to
endovascular intervention.

Mechanical thrombectomy is not without risk. Vessels can be
damaged, resulting in rupture and intracranial bleeding, and clot can be
fragmented and occlude more distal vessels. Fortunately these
complications are infrequent when the procedure is performed by trained
interventionists. [5] Guidelines and consensus documents in both Europe
and the USA recommend this form of treatment in the context of
comprehensive stroke centres, where patients with large-vessel occlusion
of the anterior circulation presenting within 6 hours after symptom
onset can be considered for mechanical thrombectomy. For those arriving
within 4.5 hours, intravenous thrombolysis is also recommended prior to
thrombectomy, unless contraindicated. [11,12] Careful selection of
patients by stroke neurologists/physicians in the setting of a stroke
centre, optimising time to reperfusion by appropriately trained
interventionists, and performance of the procedure in a
'high-volume centre' with regular audit will be critical to
providing benefit to patients.

Patient selection

Re-establishing cerebral perfusion is only of benefit if brain
tissue is not completely infarcted. Identifying patients who have
ischaemic but still viable tissue, the penumbra, is important, as is not
selecting patients with large established infarcts. Patients with large
infarcts have an increased risk of reperfusion bleeding. Various
computed tomography and magnetic resonance imaging techniques are
currently used in conjunction with clinical findings when selecting
patients. [6,9] This triage process requires expertise in image
interpretation and clinical evaluation and must be done in organised
stroke centres with stroke physicians.

Neurointerventional training

Unlike specialties and subspecialties registered with the Health
Professions Council of South Africa and examined via the Colleges of
Medicine, the training requirements for new disciplines such as
neurointervention are not yet well defined. Training standards aligned
with international norms have been adopted by the academic teaching
units in this country and form the basis for peer recognition for
proficiency as a neurointerventionist. [13] Such candidates are expected
to undergo practical training at an established unit for 1-2 years,
depending on prior clinical experience and exposure to diagnostic
neuroradiology and clinical neurosciences. Training should include a
logbook with a minimum number of supervised procedures. The South
African Neurointervention Society expects its members to participate in
annual peer review meetings, and adherence to evidence-based practice is
strongly encouraged. Assuming that any doctor working in the
endovascular field is able to do an intracranial intervention
effectively and safely without the recommended training is flawed.
Participation in short courses, workshops and industry-driven programmes
that are typically focused on use of a particular device, together with
attendance at live case demonstrations, does not replace the requirement
for supervised structured teaching. Stroke is a far more common problem
than other neurovascular conditions such as cerebral aneurysm, and the
need to train doctors only to do stroke thrombectomy rather than all
neurointervention procedures, in order to provide sufficient cover, is
currently being reviewed by international societies. It is likely,
however, that training of stroke interventionists will need to take
place in established neurointervention centres.

Mechanical thrombectomy for stroke in SA

The new era of endovascular therapy for large-vessel ischaemic
stroke is likely to present many challenges in SA. For the trial results
to be replicated and patients with acute stroke to reap the benefits of
endovascular management, it is important that mechanical thrombectomy
starts on a firm foundation. This includes identification and support of
comprehensive stroke units with appropriate referral pathways of
selected patients from primary stroke centres. One of the distinguishing
features of a comprehensive stroke centre is the availability of a
qualified neurointerventionist with protocols for thrombectomy. In the
private sector, primary stroke units are rapidly being established in
response to the advantage offered by new treatments. This is a positive
development that should result in better care and improved patient
access and includes the effective use of intravenous thrombolytics.
However, for the additional benefit of neurointerventional procedures to
be realised, we need to ensure that patients have access to
comprehensive stroke centres, and that there are sufficient trained
stroke interventionists to cover these services. This is certainly
possible with the collaboration of all role-players and if established
guidelines are followed.

Allan Taylor and David le Feuvre are neurosurgeons working in the
Division of Neurosurgery, Groote Schuur Hospital and Faculty of Health
Sciences, University of Cape Town, South Africa. Victor Mngomezulu is a
radiologist and Head of the Department of Radiology in the Faculty of
Health Sciences, University of the Witwatersrand, Johannesburg, South
Africa. Duncan Royston is a radiologist and partner at Lake, Smit
Partners in Durban, South Africa. Rohen Harrichandparsard is a
neurosurgeon working at Inkosi Albert Luthuli Hospital and the Division
of Neurosurgery, School of Clinical Medicine, College of Health
Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-
Natal, Durban, South Africa. Coert de Vries is a radiologist and head of
the Department of Radiology in the Faculty of Health Sciences,
University of the Free State, Bloemfontein, South Africa. Arthur Winter
and Francois Potgieter are radiologists and partners at Burger
Radiologists in Pretoria, South Africa.

Corresponding author: A Taylor (allan.taylor@uct.ac.za)

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